In Patent Literature 1, there is disclosed a cross-flow fan including an impeller. The impeller includes at least two support plates arranged at an interval in a rotational axis direction, and a plurality of blades arranged between the two support plates at intervals in a circumferential direction of the support plate. In this cross-flow fan, in a blade cross section orthogonal to the rotational axis of the impeller, the plurality of blades have substantially the same outer diameter. Further, in this cross-flow fan, when the longitudinal length of the blade is divided into a plurality of regions, in other words, when the longitudinal length of the blade is divided into a first region corresponding to a part adjacent to the support plate, a second region corresponding to a blade ring center portion, and a third region corresponding to a part between the first region and the second region, a blade outlet angle at a blade outer peripheral end portion in each region is increased in the order of (second region)<(first region)<(third region).
Further, in Patent Literature 2, there is disclosed a cross-flow fan including a plurality of ribs each extending from a blade leading edge portion along a blade suction surface.
Further, in Patent Literature 3, there is disclosed a transverse fan including blades each formed of a convex-shaped metal thin plate. On the convex-shaped surface, a plurality of rectangular cut and erected pieces are formed so as to erect in the convex direction. Those cut and erected pieces are arranged side by side at predetermined pitches in the blade axial direction.